Well, I can't begin to think of the odds of this sort of thing happening. My God, how many times a day does some guy arrive at an airplane, recently arrived, and proceed to hook up his fuel truck.
I mean, he was just setting up!
Or maybe fueling was done and he was unhooking and there was still pressure in the hose when it decided to let go?
Either way, the whole accident is something that could happen to ANY of us. Imagine you are doing your walkaround... Absolutely absurd, but it happened.
It's certainly no way to go.
On another tack, someone sent me this link a while back, don't know where I got it, but it shows what happens when someone, well, runs over, a hydrant. It is most certainly NOT what happened here, but I thought it might be of some interest.
http://www.aagsc.org/resources/wac/fuel_hydrants.htm
Rgrds,
PB